CN101634002A - Free-cutting alloy tool steel - Google Patents
Free-cutting alloy tool steel Download PDFInfo
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- CN101634002A CN101634002A CN200910159952A CN200910159952A CN101634002A CN 101634002 A CN101634002 A CN 101634002A CN 200910159952 A CN200910159952 A CN 200910159952A CN 200910159952 A CN200910159952 A CN 200910159952A CN 101634002 A CN101634002 A CN 101634002A
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- 229910001315 Tool steel Inorganic materials 0.000 title claims abstract description 54
- 229910045601 alloy Inorganic materials 0.000 title claims abstract description 36
- 239000000956 alloy Substances 0.000 title claims abstract description 36
- 238000005520 cutting process Methods 0.000 title abstract description 10
- 229910052750 molybdenum Inorganic materials 0.000 claims abstract description 15
- 229910052748 manganese Inorganic materials 0.000 claims abstract description 14
- 229910052721 tungsten Inorganic materials 0.000 claims abstract description 13
- 229910052804 chromium Inorganic materials 0.000 claims abstract description 10
- 239000012535 impurity Substances 0.000 claims abstract description 3
- 238000010791 quenching Methods 0.000 claims description 48
- 230000000171 quenching effect Effects 0.000 claims description 41
- 238000003754 machining Methods 0.000 claims description 21
- 229910052758 niobium Inorganic materials 0.000 claims description 6
- 229910052715 tantalum Inorganic materials 0.000 claims description 6
- 229910052719 titanium Inorganic materials 0.000 claims description 6
- 229910052760 oxygen Inorganic materials 0.000 claims description 5
- 229910052720 vanadium Inorganic materials 0.000 abstract description 6
- 229910052710 silicon Inorganic materials 0.000 abstract description 4
- 229910052759 nickel Inorganic materials 0.000 abstract description 3
- 229910052717 sulfur Inorganic materials 0.000 abstract description 2
- 229910000831 Steel Inorganic materials 0.000 description 32
- 239000010959 steel Substances 0.000 description 32
- 230000000694 effects Effects 0.000 description 24
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- 239000000463 material Substances 0.000 description 16
- 238000007669 thermal treatment Methods 0.000 description 14
- 238000012545 processing Methods 0.000 description 11
- 229910052799 carbon Inorganic materials 0.000 description 10
- 238000000034 method Methods 0.000 description 9
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 7
- 238000010438 heat treatment Methods 0.000 description 7
- 238000012360 testing method Methods 0.000 description 7
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- 229910052745 lead Inorganic materials 0.000 description 2
- 229910000734 martensite Inorganic materials 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 150000004767 nitrides Chemical class 0.000 description 2
- 239000006104 solid solution Substances 0.000 description 2
- 239000004575 stone Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 244000287680 Garcinia dulcis Species 0.000 description 1
- 229910001566 austenite Inorganic materials 0.000 description 1
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/38—Ferrous alloys, e.g. steel alloys containing chromium with more than 1.5% by weight of manganese
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Abstract
The present invention provides a free-cutting alloy tool steel comprising: c: 0.50 to 0.90 mass%, Si: 0.50 to 2.20 mass%, Mn: 0.8 mass% or more, Mn +0.08 Cr: 1.35 to 2.05 mass%, Ni: 0.01 to 0.30 mass%, Mo + 0.5W: 0.01 to 0.50 mass%, V: 0.01 to 0.15 mass%, and S: 0.03 to 0.15 mass%, the balance being Fe and unavoidable impurities; wherein the contents of Mn and Cr satisfy the following relationship: Mn/Cr: 0.10 to 0.23, and the contents of Mo, W and Mn satisfy the following relationship: /Mn: 0.55 or less.
Description
Technical field
The present invention relates to free machining alloy tool steel.More particularly, the present invention relates to so free machining alloy tool steel, the distortion that this alloy tool steel especially can prevent the heat treatment deformation that causes because of quenching and cause because of mechanical workout.
Target product of the present invention is included in when carrying out cold working and adds used cold mould and mechanical component of man-hour by forging or progressive die press.
The example of cold mould comprises block punch (block punch), button die (buttondie), guiding punch (pilot punch), straight-through punch (straight punch), stretching convex die (drawing punch), stretching punch die (drawing die), crooked formed punch/air-bend die (bending punch/die), convex model cutter (punch-type cutter)/roll-type cutter, rolling type of line or the rolling type of groove (thread or groove rolling type), the forging type, gear punching parts/piercing die, and swage die (swaging die).
The example of mechanical component comprises base plate, guide plate, dividing plate, stripper (stripper), threaded plug, baffle plate (retainer), guide bush (guide bush), defends plate (dowel bush), guide plate (stripper guide), ejector pin (knock out pin), guide pillar (guide post), retainingf key (fixing key), plastic moulding tool, screwed part, cam member (camcomponent), sealing plate and instrument (gauge).
Mould in the above-mentioned application or member also comprise cold mould or the member through surface treatment (for example CVD processing, PVD processing, TD handle and nitriding treatment) or surface modification (for example shot peening).
Background technology
Traditionally, carbon tool steel, alloy tool steel that the alloying element addition is few, wherein add cold mould steel that a large amount of Cr are arranged etc. and be used as tool steel always.
Because the addition of carbon tool steel or alloy tool steel interalloy element is few, so it has the relatively poor shortcoming of hardening capacity.
In this tool steel, a large amount of Mn is added into to attempt to improve its hardening capacity.Yet although Mn improves hardening capacity effective elements the most, if add a large amount of Mn, can make residually after quenching has a large amount of residual austenites.Therefore, the adding nature of Mn can be restricted, and the Mn that is added can not surpass certain amount.
Therefore, for wherein mainly improving for the conventional tool steel (as carbon tool steel and alloy tool steel) of hardening capacity the hardening capacity deficiency that it is initial by adding Mn.
Therefore, when steel is quenched, must cool off (as water-cooled or oil cooling) fast, and in this case, in process of cooling, because the difference of rate of cooling causes between the surface of product and inside or produce bigger temperature head between the different position of the wall thickness of product, thereby produces and quenching (thermal treatment) relevant obvious distortion (heat treatment deformation).
Owing to there are these problems,, be 30mm or littler small-sized goods thereby its target product is restricted to thickness so carbon tool steel or alloy tool steel can not be applied to large mould etc.
On the other hand, owing to added a large amount of alloying elements, therefore has enough hardening capacity in the cold mould steel.
In cold mould steel, generally add a large amount of Cr as the element that improves hardening capacity.
When add-on was identical, hardening capacity that Cr produced improved the effect that effect is less than Mn, but can add a large amount of Cr, and therefore the hardening capacity of this cold mould steel will be higher than the carbon tool steel that only added Mn or the hardening capacity of alloy tool steel far away.
Therefore, progressively cooling is enough to the rate of cooling when quenching, and can suppress the material deformation that causes because of the above-mentioned thermal treatment that carbon tool steel or alloy tool steel are applied.
Yet in the situation of cold mould steel, a large amount of Cr that add can cause a large amount of carbide to separate out in order to improve wear resistance.Therefore, when cold mould steel is carried out such as the cutting and grinding mechanical workout the time, the carbide harder than base material can make the cutting edge of cutting tool or grinding stone wear and tear.
In this case, the amount of carbide is many more, can strengthen the wearing and tearing to blade or grinding stone more, and the resistance that material is processed is increased, thereby is difficult to this material is processed.
This shows in the course of processing can apply bigger stress to material, and owing to also residual in this material when process finishing this big stress is arranged, thereby complete or partial distortion takes place material.
Promptly, thereby having added a large amount of Cr therein separates out under the situation of cold mould steel of a large amount of carbide, thereby although since its to have high-hardenability heat treatment deformation in quenching process less, in mechanical processing process, still have the problem of the bigger machining deformation of generation.
Mention that along band the technology relevant with the present invention comprises those disclosed in following patent documentation 1,2 and 3.
Patent documentation 1:JP-A-11-131182 (terminology used here " JP-A " is meant " unexamined Japanese Patent Application Publication ")
Patent documentation 2:JP-A-2002-167644
Patent documentation 3:JP-A-2001-234278
Summary of the invention
Finished the present invention based on above-mentioned situation; the purpose of this invention is to provide a kind of free machining alloy tool steel; material deformation that thermal treatment when this alloy tool steel can be guaranteed because of quenching causes and the material deformation that causes because of mechanical workout all are suppressed, and can obtain as cold mould or the required hardness of mechanical component.
That is, the invention provides following every content.
1. free machining alloy tool steel comprises:
C:0.50 quality % to 0.90 quality %,
Si:0.50 quality % to 2.20 quality %,
Mn:0.80 quality % or higher,
Mn+0.08Cr:1.35 quality % to 2.05 quality %,
Ni:0.01 quality % to 0.30 quality %,
Mo+0.5W:0.01 quality % to 0.50 quality %,
V:0.01 quality % to 0.15 quality % and
S:0.03 quality % to 0.15 quality %,
Surplus is Fe and unavoidable impurities;
Wherein the content of Mn and Cr satisfies following relation:
Mn/Cr:0.10 to 0.23, and
The content of Mo, W and Mn satisfies following relation:
(Mo+0.5W)/Mn:0.55 or lower.
(chemical symbol of top each element is represented the content of each element (quality %); Following every also identical.)
2. according to item 1 described free machining alloy tool steel, also contain Ca and O, the content of Ca and O is:
Ca:0.0001 quality % to 0.0100 quality % and
O:0.0100 quality % or lower.
3. according to item 1 or 2 described free machining alloy tool steels, except containing S, also contain the one or both in the following combination:
Se+Te:0.01 quality % to 0.15 quality % and
Pb+2Bi:0.01 quality % to 0.15 quality %.
4. according to any described free machining alloy tool steel in the item 1 to 3, also contain one or more elements among Nb, Ta, Ti and the Zr, the content of these elements is:
Nb+Ta+Ti+Zr:0.01 quality % to 0.15 quality %.
5. according to any described free machining alloy tool steel in the item 1 to 4, use this alloy tool steel after under 1,000 ℃ to 1,050 ℃ temperature, quenching.
Brief Description Of Drawings
Fig. 1 is the figure that the relation between the Cr content and Mn content in the alloy tool steel of the present invention is shown.
Fig. 2 is for illustrating the influence of (Mo+0.5W)/Mn to quenching/tempered-hardness.
Embodiment
The present invention has following feature: thereby by by adding the high-hardenability that synergy between the effect that effect that Mn produces and interpolation Cr produce has been guaranteed alloy tool steel, and make the addition of Cr reduce owing to adding the hardening capacity increase effect that Mn produced, thereby suppressed the formation of carbide and improved the machinability deterioration that causes by carbide; Although the hardness when interpolation Mn can make quenching and Annealed Strip usually reduces, yet because the reduction of the addition of Mo, so kept required hardness.
More specifically, as main feature, at the addition of Mn is under 0.8 quality % or the higher precondition, the interpolation scope of Mn+0.08Cr is 1.35 quality % to 2.05 quality %, the ratio of Mn/Cr is set to 0.1 to 0.23, thereby makes and reach balance between the addition of the addition of Mn and Cr, in addition, (Mo+0.5W)/and the ratio of Mn is set to 0.55 or lower, thus make and reach balance between the addition of Mn and the addition (Mo+0.5W).
The same with the cold mould steel of routine, can suppress the material deformation that the thermal treatment when quenching causes by guaranteeing sufficiently high hardening capacity.In this case, preferably improve the addition of alloying element.
On the other hand, can suppress the material deformation that causes by mechanical workout by the amount that reduces carbide.That is,, preferably reduce the addition of alloying element from the angle of the material deformation that causes by mechanical workout.
These require conflicting, but can be by at the element that forms carbide and be helpless to form and separately consider the alloying element that adds between the element of carbide, to overcome this problem.
The main example that forms the element of carbide comprises C, Cr, Mo, W and V, therefore preferably reduces the amount of these elements as far as possible.
On the other hand, the main example that is helpless to form the element of carbide comprises Si, Mn and Ni, therefore, preferably improves the amount of these elements as far as possible.
Therefore, the Cr that is substituted in heavy addition in the conventional cold mould steel with Mn is important.
In addition, it also is important adding Mo, W and V as far as possible on a small quantity.
Yet because cold mould or the needed hardness of mechanical component are HRC 58 or higher, so the addition of C is necessary for 0.50% or higher.
The present invention is based on this thinking or discovery and be accomplished.
Fig. 1 illustrates the relation between the addition of the addition of Cr in the alloy tool steel of the present invention and Mn.In Fig. 1, regional H is the zone of the addition of Cr among the present invention and Mn.
According to the present invention, the thermal treatment in the time of not only can reducing the quenching by alloy tool steel and the distortion that causes, the distortion that the unrelieved stress in the time of also can reducing because of mechanical workout causes.
In addition, according to the present invention, the addition of Cr (its for expensive alloying element) can reduce, thereby makes the cost of material reduce, and helps processing, and processes required cost thereby reduced, and making can be with lower cost-effective ground mfg. moulding die etc.
According to the present invention, when the content of Ca and O all met above-mentioned 2 described predetermined amounts, the processibility of alloy tool steel can be further enhanced.
In addition, when adding Se+Te or Pb+2Bi according to above-mentioned item 3, processibility can be further enhanced.
In addition, when according to one or more elements among above-mentioned item 4 interpolation Nb, Ta, Ti and the Zr, because the formed carbide of these elements, nitride etc. are to the pinning effect (pinning effect) of crystal grain, thereby remedied the minimizing that reduces the carbide content that causes owing to the addition of Cr, and can prevent crystal grain generation roughening.
Mention along band,, usefully, improve the amount of dissolved element under quenching temperature in order to ensure hardening capacity.
Therefore, preferably quenching temperature is made as 1,000 ℃ or higher (and being 1,050 ℃ or lower).
In other words, preferably, be prerequisite with the purposes after under above-mentioned high temperature, quenching, set up components system.
Under said temperature, quench and also have following implication.
Traditionally, as tool steel, quantitatively accounting for most is Cr and the steel after quenching under 1,000 ℃ to 1,050 ℃ the quenching temperature that has wherein added predetermined amount, therefore, the heat treatment furnace that is used to quench also is to quench as prerequisite under this temperature, that is, to be used for 1 usually, the stove that quenches under 000 ℃ to 1,050 ℃.
If quenching temperature is lower than said temperature, then its device need be reinstalled, thereby makes the cost of quench treatment improve.
When the suitable quenching temperature of material is 1,000 ℃ to 1,050 ℃, need not to reinstall heat treatment furnace, therefore can carry out quench treatment with lower cost in a conventional manner.
Below, the reason that will limit each used among the present invention chemical ingredients is elaborated.Incidentally, the unit of component proportions is a mass percent.In this article, all are identical with the per-cent that is limited by weight respectively by per-cent that quality limits in the present specification.
C:0.50% to 0.90%
Need add C according to required hardness, thereby when quenching, form martensite and improve hardness.In order to obtain HRC 58 or higher hardness, need add 0.50% or higher C at least.Yet if the add-on of C is too high, the amount of carbide can increase pro rata.Therefore, its add-on need be 0.90% or lower.From above-mentioned angle, its add-on is preferably 0.65% to 0.80%.
Si:0.50% to 2.20%
The dissolving of Si solid, thus the effect that martensite hardness is improved produced.Because this element can improve hardening capacity, and can not form carbide, so its add-on is 0.50% or higher.The add-on of Si is set to 2.20% or lower, and this is because if its add-on is too high, then can form ferrite and quenching hardness is reduced.
Mn：≥0.80％
Mn is the element that effectively improves hardening capacity.As the substitute element of Cr, Mo, W and V and the hardening capacity that reaches, its add-on is necessary for 0.8% or higher in order to ensure this element.
Mn/Cr:0.10 to 0.23
For the amount that reduces carbide and guarantee hardening capacity, preferably improve the ratio of Mn.If above-mentioned ratio is lower than described lower limit, then the amount of carbide can be too high, and can not reduce the strain that produces because of processing fully, if yet its ratio surpasses the described upper limit, the too high levels of Mn then, and can produce a large amount of residual austenites, thus can not guarantee hardness.In addition, if above-mentioned ratio surpasses the described upper limit, then the amount of Cr is low excessively, thereby makes the hardening capacity deficiency.
Mn+0.08Cr:1.35% to 2.05%
The total addition level of Mn+0.08Cr is big more, and hardening capacity is improved more, yet if its total addition level is too high, can form a large amount of residual austenites, thereby can not guarantee hardness, and if its total addition level is too small, then can make the hardening capacity deficiency.Mention along band the coefficient 0.08 of Cr is meant with Mn to be benchmark, Cr is to the contribution proportion of hardening capacity.
Ni:0.01% to 0.30%
Ni is identical with the effect of Mn.In order to compensate the hardening capacity that realizes by Mn, can add 0.01% or higher Ni.Its add-on is 0.30% or lower, and this is because if its too high levels, and then austenitic residual volume can increase, thereby hardness is reduced.
Mo+0.5W:0.01% to 0.50%
Mo and W have same effect.The effect that W played is half of effect of Mo, so its coefficient is 0.5.Owing to make that by adding Mn and Cr the hardening capacity of alloy tool steel is almost enough high, therefore preferably should not add these elements.Yet,, need to add Mo and W, and its add-on is necessary for 0.01% from the angle of hardness.If its add-on is too high, the amount of unwanted carbide can increase, so its add-on is 0.50% or lower.
(Mo+0.5W)/Mn：≤0.55
Add Mo+0.5W in large quantities and also can cause following problem.
In the present invention, the add-on of Mn is higher, is 0.8% or higher.Under the add-on condition with higher of Mn, if the add-on of Mo+0.5W is too high, then Ms point or Mf point can significantly reduce, thereby make the hardness under as-quenched condition and Annealed Strip reduce, and can not obtain HRC 58 or higher hardness.Therefore, in the present invention, in order to obtain HRC 58 or higher hardness, the ratio of (Mo+0.5W)/Mn is made as 0.55 or lower.
Fig. 2 illustrates the relation between (Mo+0.5W)/Mn and the quenching/tempered-hardness.
When composition of steel is C:0.60% to 0.75%, Si:0.96% to 1.53%, Mn:0.81% to 1.53%, Cr:6.65% to 7.95%, Mn/Cr:0.12% to 0.21%, Mn+0.08Cr:1.36% to 1.98%, Ni:0.15% to 0.16%, Mo:0.001% to 2.52%, (Mo+0.5W)/Mn:0.005 to 3.11, V:0.02% to 0.09% and S:0.05%, surplus be Fe (promptly, except (Mo+0.5W)/Mn, other is a listed composition in above-mentioned 1) time, obtain the result shown in the table 2, and, its numerical value is carried out multiple change to study its effect in order to study the effect of (Mo+0.5W)/Mn.
In Fig. 2, specifically determine the relation between (Mo+0.5W)/Mn and the quenching/tempered-hardness in such a way.
The steel fusion that in vacuum induction furnace, will have said components, making the ingot casting of 50kg, and with this ingot casting 1,160 ℃ of following soaking 10 hours are forged under the temperature between 900 ℃ to 1,160 ℃ subsequently, be of a size of 45mm * 45mm * 1 with formation, the square rod of 500mm.
The tool steel of square rod shape is carried out Spheroidizing Annealing handle, that is, progressively cool off since 900 ℃ with 20 ℃/hour rate of cooling, and the material machining after the thermal treatment is become the square of about 20mm * 20mm * 20mm.
These samples are heated 30 minutes or longer time down at 1,030 ℃, quench, heat tempering 60 minutes or longer time down at 180 ℃ subsequently by oil cooling.
After finishing thermal treatment, remove scale by grinding, subsequently the hardness of measure sample.
Fig. 2 be illustrate after quenching/tempering hardness with (Mo+0.5W)/figure of the relation of Mn.
In the result of Fig. 2, main component all is positioned at claim scope of the present invention, yet, (Mo+0.5W)/effect of Mn is very remarkable.
Can find out from the result of Fig. 2, in order to obtain required HRC 58 such as cold mould or higher hardness, (Mo+0.5W)/Mn is necessary for 0.55 or lower.
This is because in compositional range of the present invention, if add Mo or W too much, then unconverted residual austenite structure can increase when quenching, thereby can not obtain this hardness.
On the other hand, if the add-on of Mo or W is low excessively, then can cause the decline of quenching/tempered-hardness or the decline of hardening capacity usually.Yet, in the present invention, stipulated add-on, thereby can obtain sufficiently high quenching/tempered-hardness such as compositions such as C, Mn and Cr.
Aspect hardening capacity, particularly, as Mn+0.08Cr having been carried out qualification, necessary addition is also stipulated.
V:0.01% to 0.15%
V is the element that has same purpose with Mo and W, and in the present invention, its add-on is 0.01% to 0.15%.
S:0.03% to 0.15%
S combines with Mn and forms the MnS compound.This combination can make machinability or abrasive machine processibility strengthen.Yet, if its add-on is lower than 0.03%, can not obtain this reinforced effects, even and the add-on of this element has surpassed 0.15%, it is saturated that this effect has also reached.For these reasons, be limited to 0.15% on it.
Ca:0.0001% to 0.0100%
When also adding Ca when adding S, machining property enhanced effect can be improved.This is because the Ca oxide compound has the effect of protection instrument.In order fully to form the Ca oxide compound, the add-on of Ca need be 0.0001% or higher.Even its add-on surpasses 0.0100%, it is saturated that this effect has also reached.Therefore, be limited to 0.0100% on it.
O：≤0.0100％
This is the element that unavoidably contains in the steel.In order to form the Ca oxide compound, the content of O need be 0.0100% or lower.
Se+Te:0.01% to 0.15%, Pb+2Bi:0.01% to 0.15%
These elements all are the elements that strengthen machinability or abrasive machine processibility.Depend on as raw-material steel scrap, add these elements sometimes in a large number, so these elements can be used as the substitute element of the S of interpolation.In order to obtain machinability enhanced effect by adding these elements, the add-on of these elements need be higher than the lower limit of top defined.Yet even the add-on of these elements has surpassed the upper limit of top defined, it is saturated that its effect has also reached.
Nb+Ta+Ti+Zr:0.01% to 0.15%
These elements all have the effect that forms carbide or nitride and prevent crystal grain generation roughening under quenching and maintenance temperature.In the present invention, reduced the add-on of Cr, Mo, W and V as much as possible, so the amount of carbide is lower.As a result, be easy to take place the roughening of crystal grain.In order to prevent crystal grain generation roughening and suppress flexible and reduce that total add-on of these elements can be 0.01% or higher.Yet even the add-on of these elements surpasses 0.15% the upper limit, its effect also can reach capacity.
At this on the one hand, for each contained in the steel of the present invention element, according to an embodiment, the minimum content of each element is an employed smallest non-zero quantity in the example of the steel of being developed of concluding in the table 1 in the steel.According to another embodiment, the high-content of each element is an employed maximum amount in the example of the steel of being developed of concluding in the table 1 in the steel.
Quenching temperature: 1,000 ℃ to 1,050 ℃
The quenching temperature of carbon tool steel or special tool steel (corresponding to SK or SKS) is lower than 1,000 ℃, and therefore, the amount of solid solution element is lower, thereby causes hardening capacity relatively poor.The quenching temperature of cold mould steel (corresponding to SKD) is 1,000 ℃ or higher, thereby the amount of solid solution element increases.In order to ensure hardening capacity, preferably quenching temperature is 1,000 ℃ or higher.Yet, if heating, because the roughening of particle diameter can cause toughness lower above under 1,050 ℃ the temperature.Therefore, preferably be no more than 1,050 ℃ temperature.
Example
120kg steel fusion in vacuum induction furnace that will have various components shown in the table 1, and use the ingot shape of Φ 250mm * 450mm to cast this melt.Ingot casting is heated under 1,150 ℃ to 1,200 ℃ and remain under this temperature, it is forged be the square of 65mm subsequently.After forging, carry out Spheroidizing Annealing, thereby obtain HRC 25 or lower than soft.
This is cut into through forged material respectively test required predetermined size.After cutting, materials processing is become each sample, and under the quenching/tempering temperature shown in the table 2, heat-treat.Hardness after this thermal treatment is shown in Table 2 (when hardness value is bracketed by bracket, the hardness under the quenching temperature in the expression bracket) equally.In addition, about the evaluation of hardening capacity and boring processibility, under the Spheroidizing Annealing state, test.
Mention along band, carry out evaluation test according to each performance shown in the following mode his-and-hers watches 2.
(A) hardening capacity
The sample of preparation φ 3mm * 10mm, and under the quenching temperature shown in the table 2, kept 5 minutes, be cooled to 100 ℃ or lower with uniform rate of cooling subsequently.When changing rate of cooling, for each rate of cooling, will be used to obtain hardness is that HRC 58 or the higher required minimum limit rate of cooling of sample are expressed as hardening capacity.
The sample that limit rate of cooling is lower can be evaluated as has higher hardening capacity.
Should with in required hardening capacity be 15 ℃/minute or lower.
(B) the warpage rate after the thermal treatment
The sample of preparation 20mm * 50mm * 100mm, and under the quenching temperature shown in the table 2, kept 30 minutes, quench with the rate of cooling that is expressed as hardening capacity subsequently.In addition, carry out tempering subsequently.
By the three-dimensional dimension measuring apparatus, at the length of 100mm, the warpage rate of measure sample after thermal treatment has much.In the length range of 100mm, measure the difference between maximum height and the minimum constructive height, and represent with the form of this difference size/100mm.
Generally with regard to precision, the size of this difference need be 0.1mm or lower.To be in that the difference under the state is set at 0.020mm (0.020%) or lower before the thermal treatment.
(C) boring processibility
The sample of preparation 50mm * 50mm * 200mm, and use and through the SKH51 of vapour cure HSS drill bit (φ 6mm) it is carried out punching processing.
Adding man-hour, under the controlled condition of dry process (0.15mm/ changes, and hole depth is 15mm), coming the repetition punching processing, till drill bit is damaged owing to fusion or fracture by changing cutting speed.Progressively reduce cutting speed, and will obtain 70 or the cutting speed during more a plurality of hole be evaluated as the boring life-span.Bigger cutting speed is represented more excellent boring processibility.
(D) grindability
The sample of preparation 20mm * 50mm * 200mm, and with the 0.5mm processing of swiping of swiping from the surface of 50mm * 200mm of plane mill.Be 100 the process period of supposing comparative example 6, estimates the scraping required time of 0.5mm.When required time is the one half, then grindability is chosen as 200.The big more expression grindability of numerical value is good more.
(E) the warpage rate after the processing
After estimating above-mentioned grindability, use the three-dimensional dimension measuring apparatus, measure the difference between the maximum height and minimum constructive height in the length range of 100mm.Generally with regard to precision, the size of this difference need be 0.1mm or lower.To be in that the difference under the state is set at 0.020mm (0.020%) or lower before the ground finish.
(F) charpy impact test
According to the method described in the JIS Z 2242 sample is tested.About sample, preparation 10R recess sample, its notch part is 10R, and the degree of depth is 2mm.At room temperature carry out this test, and estimate this numerical value by impact value.
(G) fatigue strength test
By the method described in the JIS Z2274 sample is tested.Used sample is No. 1 sample (parallel portion: φ 8mm), at room temperature test.To repeat this test 10
7Intensity evaluation when not causing fracture when inferior is a breaking limit.
These evaluation results are shown in Table 2.
Can find out from the result of table 2, not add relatively the using in the steel 1 of S, satisfy the requirement of boring processibility.
Relatively using in the steel 2 (wherein, the addition substantial deviation scope of the present invention of C and Si, and contain a large amount of Mo, W and V), form a large amount of carbide, and grindability is relatively poor and processing after the warpage rate bigger.In addition, because the existence of carbide, make performance generation deterioration aspect charpy impact intensity or fatigue strength.
Relatively using in the steel 3,4 and 5 (wherein, Mn/Cr is low excessively, and the addition of C exceeds scope of the present invention), form a large amount of carbide, and with relatively use steel 2 similar, its performance generation deterioration.
Relatively using in the steel 6,7 and 8 (wherein, Mn/Cr is too high, and Mn+0.08Cr is low excessively) its hardening capacity deficiency.Therefore, the cooling after the quenching needs cooling fast, and the warpage rate after the thermal treatment is bigger.In addition, relatively use in the steel, have only when quenching temperature is lower than 1,000 ℃, just can obtain HRC 58 or higher required hardness at these.
Relatively using in the steel 9,10 and 11 (wherein, Mn/Cr is too high) its hardening capacity deficiency.Therefore, the cooling after the quenching needs cooling fast, and the warpage rate after the thermal treatment is bigger.
In addition, obtained HRC 58 or higher required hardness, when quenching temperature is 1,000 ℃ to 1,050 ℃, but can not obtain required hardness although be lower than in quenching temperature under 1,000 ℃ the condition.
Relatively compare with steel with these, for these all performances, steel of the present invention all obtains good result.
Although the present invention is described in detail, it will be apparent to those skilled in the art that and to carry out various modifications and change to the present invention under the premise without departing from the spirit and scope of the present invention with reference to specific embodiments.
The present invention is based on Japanese patent application No.2008-189726 that submitted on July 23rd, 2008 and the Japanese patent application No.2009-091602 that submitted on April 3rd, 2009, its content is incorporated herein by reference.
Claims (9)
1. free machining alloy tool steel comprises:
C:0.50 quality % to 0.90 quality %,
Si:0.50 quality % to 2.20 quality %,
Mn:0.8 quality % or higher,
Mn+0.08Cr:1.35 quality % to 2.05 quality %,
Ni:0.01 quality % to 0.30 quality %,
Mo+0.5W:0.01 quality % to 0.50 quality %,
V:0.01 quality % to 0.15 quality % and
S:0.03 quality % to 0.15 quality %,
Surplus is Fe and unavoidable impurities;
Wherein the content of Mn and Cr satisfies following relation:
Mn/Cr:0.10 to 0.23, and
The content of Mo, W and Mn satisfies following relation:
(Mo+0.5W)/Mn:0.55 or lower.
2. free machining alloy tool steel according to claim 1 also contains Ca and O, and the content of described Ca and O is:
Ca:0.0001 quality % to 0.0100 quality % and
O:0.0100 quality % or lower.
3. free machining alloy tool steel according to claim 1, except containing S, also contain the one or both in the following combination:
Se+Te:0.01 quality % to 0.15 quality % and
Pb+2Bi:0.01 quality % to 0.15 quality %.
4. free machining alloy tool steel according to claim 2, except containing S, also contain the one or both in the following combination:
Se+Te:0.01 quality % to 0.15 quality % and
Pb+2Bi:0.01 quality % to 0.15 quality %.
5. free machining alloy tool steel according to claim 1 also contains one or more elements among Nb, Ta, Ti and the Zr, and the content of described element is:
Nb+Ta+Ti+Zr:0.01 quality % to 0.15 quality %.
6. free machining alloy tool steel according to claim 2 also contains one or more elements among Nb, Ta, Ti and the Zr, and the content of described element is:
Nb+Ta+Ti+Zr:0.01 quality % to 0.15 quality %.
7. free machining alloy tool steel according to claim 3 also contains one or more elements among Nb, Ta, Ti and the Zr, and the content of described element is:
Nb+Ta+Ti+Zr:0.01 quality % to 0.15 quality %.
8. free machining alloy tool steel according to claim 4 also contains one or more elements among Nb, Ta, Ti and the Zr, and the content of described element is:
Nb+Ta+Ti+Zr:0.01 quality % to 0.15 quality %.
9. according to any described free machining alloy tool steel in the claim 1 to 8, use this alloy tool steel after under 1,000 ℃ to 1,050 ℃, quenching.
Applications Claiming Priority (6)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2008-189726 | 2008-07-23 | ||
| JP2008189726 | 2008-07-23 | ||
| JP2008189726 | 2008-07-23 | ||
| JP2009091602A JP5504680B2 (en) | 2008-07-23 | 2009-04-03 | Free-cutting alloy tool steel |
| JP2009091602 | 2009-04-03 | ||
| JP2009-091602 | 2009-04-03 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101634002A true CN101634002A (en) | 2010-01-27 |
| CN101634002B CN101634002B (en) | 2013-07-31 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2009101599527A Expired - Fee Related CN101634002B (en) | 2008-07-23 | 2009-07-23 | Free-cutting alloy tool steel |
Country Status (6)
| Country | Link |
|---|---|
| EP (1) | EP2154260B1 (en) |
| JP (1) | JP5504680B2 (en) |
| KR (1) | KR101608087B1 (en) |
| CN (1) | CN101634002B (en) |
| AT (1) | ATE503853T1 (en) |
| DE (1) | DE602009000974D1 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104204262A (en) * | 2011-12-28 | 2014-12-10 | Posco公司 | Wear-resistant austenitic steel having superior machinability and ductility, and method for producing same |
| CN104640654A (en) * | 2012-08-20 | 2015-05-20 | 日立金属株式会社 | Method for cutting cold work tool steel, and method for producing cold-working die material |
| CN106119738A (en) * | 2016-06-28 | 2016-11-16 | 浙江工贸职业技术学院 | A kind of alloy material for marine drilling platform gauge valve spool and manufacture method |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| EP2543559B1 (en) | 2010-03-04 | 2014-09-03 | Honda Motor Co., Ltd. | Vehicle seat belt device |
| US9735555B2 (en) | 2015-08-27 | 2017-08-15 | Eaton Corporation | Mechanical door interlock device for protecting power electrical switching apparatus and users |
| US20210262050A1 (en) * | 2018-08-31 | 2021-08-26 | Höganäs Ab (Publ) | Modified high speed steel particle, powder metallurgy method using the same, and sintered part obtained therefrom |
| WO2020161359A1 (en) * | 2019-02-08 | 2020-08-13 | Rovalma, S.A. | Low cost high performant tool steels |
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| SE459421B (en) * | 1987-10-28 | 1989-07-03 | Uddeholm Tooling Ab | APPLICATION OF A TOOL STEEL FOR CARBON PLATE PRESSURE TOOL |
| JPH04280942A (en) * | 1991-01-24 | 1992-10-06 | Daido Steel Co Ltd | Cast steel excellent in machinability |
| JPH11131182A (en) | 1997-10-31 | 1999-05-18 | Daido Steel Co Ltd | Cold tool steel for flame hardening |
| JP2001020041A (en) * | 1999-07-08 | 2001-01-23 | Hitachi Metals Ltd | Tool steel excellent in weldability and machinability and tool and die |
| JP2001049394A (en) * | 1999-08-17 | 2001-02-20 | Hitachi Metals Ltd | Tool steel excellent in weldability and machinability, and die using the same |
| JP2001064754A (en) * | 1999-08-30 | 2001-03-13 | Hitachi Metals Ltd | Tool steel with excellent weldability and machinability and suppressed secular change, and die using the same |
| JP2001234278A (en) | 2000-02-16 | 2001-08-28 | Daido Steel Co Ltd | Cold tool steel excellent in machinability |
| JP2001294974A (en) * | 2000-04-12 | 2001-10-26 | Hitachi Metals Ltd | Tool steel excellent in machinability and small in dimensional change cause by heat treatment and its producing method |
| JP2001316769A (en) * | 2000-05-10 | 2001-11-16 | Daido Steel Co Ltd | Cold tool steel |
| JP2002167644A (en) | 2000-11-30 | 2002-06-11 | Daido Steel Co Ltd | Cold tool steel having constant deformation on treatment and method for producing cold tool using the steel |
| JP3602102B2 (en) * | 2002-02-05 | 2004-12-15 | 日本高周波鋼業株式会社 | Hot tool steel |
| JP4403875B2 (en) * | 2004-05-14 | 2010-01-27 | 大同特殊鋼株式会社 | Cold work tool steel |
| JP2007197746A (en) * | 2006-01-25 | 2007-08-09 | Daido Steel Co Ltd | Tool steel |
| JP5226953B2 (en) | 2007-02-01 | 2013-07-03 | 花王株式会社 | Detergent particles |
| JP5012384B2 (en) | 2007-10-04 | 2012-08-29 | 三菱電機株式会社 | Surface treatment method |
-
2009
- 2009-04-03 JP JP2009091602A patent/JP5504680B2/en active Active
- 2009-07-23 DE DE602009000974T patent/DE602009000974D1/en active Active
- 2009-07-23 KR KR1020090067386A patent/KR101608087B1/en active IP Right Grant
- 2009-07-23 AT AT09009568T patent/ATE503853T1/en active
- 2009-07-23 EP EP09009568A patent/EP2154260B1/en not_active Not-in-force
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104204262A (en) * | 2011-12-28 | 2014-12-10 | Posco公司 | Wear-resistant austenitic steel having superior machinability and ductility, and method for producing same |
| CN104640654A (en) * | 2012-08-20 | 2015-05-20 | 日立金属株式会社 | Method for cutting cold work tool steel, and method for producing cold-working die material |
| CN104640654B (en) * | 2012-08-20 | 2017-05-10 | 日立金属株式会社 | Method for cutting cold work tool steel, and method for producing cold-working die material |
| CN106119738A (en) * | 2016-06-28 | 2016-11-16 | 浙江工贸职业技术学院 | A kind of alloy material for marine drilling platform gauge valve spool and manufacture method |
Also Published As
| Publication number | Publication date |
|---|---|
| ATE503853T1 (en) | 2011-04-15 |
| JP5504680B2 (en) | 2014-05-28 |
| DE602009000974D1 (en) | 2011-05-12 |
| CN101634002B (en) | 2013-07-31 |
| JP2010047831A (en) | 2010-03-04 |
| EP2154260A1 (en) | 2010-02-17 |
| EP2154260B1 (en) | 2011-03-30 |
| KR20100010918A (en) | 2010-02-02 |
| KR101608087B1 (en) | 2016-03-31 |
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